Controlled Impedance Traces on Printed Circuit Boards (PCB), Cables, and Connectors

Controlled impedance trace (PCB) measurement with Sequid time domain reflectometer STDR-65 Due to increasing clock rates in high speed digital systems the necessity of controlled impedance PCBs is growing rapidly. Additionally, cables and connectors must meet high frequency design specifications and controlled impedance specs. Sequid's DTDR-65 (differential & single-ended TDR resp. controlled impedance measurements on PCB) and STDR-65 (single-ended only) helps you to measure wave impedances of PCBs, cables, and connectors very comfortably. The high precision TDR devices are delivered with an easy to use application software, enabling even inexperienced users to carry out impedance measurements quickly. The convenient compilation of PDF reports is highly appreciated by many of our customers.

Controlled Impedance Trace on PCB measured with Sequid DTDR-65 time domain reflectometer (PDF-Report)
Controlled Impedance Trace Measurement of PCB (PDF-Report)


In PCB production processes generally so-called controlled impedance test coupons are measured. One of these is normally located on the PCB-margin and its controlled impedance traces are taken as representatives for those of the whole manufactured panel. These measurements are quickly and easily executable with our TDR devices. In contrast to other systems on the market, Sequid TDRs are well suited for evaluating the controlled impedances traces of real interest, i.e. for impedance traces located directly on the readily manufactured PCB. To this end Sequid offers specialized Precision TDR-Probes ensuring reliable contact to the controlled impedance traces under test, even on fully assembled PCB.

Modern digital or high frequency systems obviously not only consist of controlled impedance PCBs, and are thus possibly also impaired by cables and connectors, not complying with high frequency design specifications. Their controlled impedances can have a significant impact on the systems performance. The impedances of these components can also be measured with Sequids DTDR-65 resp. STDR-65. If you have further questions related to the controlled impedance topic, please contact us directly. We will be glad to assist you.


Required accessories for controlled impedance measurements

  • Time domain reflectometer DTDR-65 (diff./sgl.-ended) or STDR-65 (sgl.-ended) controlled impedance measurements
  • Base application software
  • Software module Ωplus (PDF info flyer) for controlled impedance measurements
  • SMA cable SPMC-P (diff.) or SCC-P (sgl.-ended)
  • Differential TDR probe SDTP-E (economy, for test coupons traces)
  • Single-ended TDR probe SSTP-E (economy, for test coupons traces)
  • Differentielle TDR probe SDTP-P (precision, in-circuit controlled impedance measurements)
  • Single-ended TDR probe SGTL-TDRP-K01 (precision, in-circuit controlled impedance measurements)
  • Calibration kit